Lesson Plans for:
Section 1.3
Segments, Rays, Parallel Lines and Planes
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Most instruction will be done through a work-along notes sheet. This will provide an organized way
to give students the definitions and examples.
At the top of the second page of notes, students are told they will make a model to help envision the
different types of lines, particularly skew lines. The teacher-directions for this simple model is at the
bottom of this page.
At the end of the notes, there are several questions that students can work on their own, and then the
class can go over as a check for understanding.
Homework has not been chosen yet.
*Note: The diagrams in the work-along were taken from the on-line Prentice Hall text, including the 1.3 text
and also Checkpoint Quiz #1.
Teacher Plans for making model.
Each student should
-bring in a tissue box (empty or full)
-be provided with two pipe cleaners and a strip of masking tape (6 inches or so would be
plenty)
Students will tape a pipe cleaner to any edge of their box.
Now ask them to place the second pipe cleaner (not taping yet) on an edge where they would be
intersecting. Visually check students’ placements. Do the same for a parallel edge, asking them to
find several.
Finally ask them to place the pipe cleaner so that the two lines are skew. This is where they will
tape it into place. Students can leave full tissue boxes for a bit of extra credit. Keeping the tissue
boxes with their skew lines in the classroom will help reinforce to students what skew lines look
like.
1.3 Segments, Rays, Parallel Lines and Planes
Part I:
We are going to study figures that are a part of a line.
FIGURE
DEFINITION
Segment
Ray
Opposite
Rays
Name the segments
Name the rays
Name a pair of opposite rays
Part II:
Now we will look at the different ways that two lines may or may not intersect.
TYPE OF LINES ARE THEY IN THE DO THEY
EXAMPLE
SAME PLANE?
Intersecting
Parallel Lines
Skew Lines
INTERSECT?
EXAMPLES
Skew lines are probably the most difficult to envision. We will make a model to help you see them.
EXAMPLE:
Name all segments that intersect DC
Name all segments that are parallel to DC
Name all segments that are skew to DC
Part III:
One last definition.
Parallel Planes are ____________________________________________.
Name a plane that is parallel to Plane ABCD
Name another pair of parallel planes.
Now try answering these questions on your own, using the diagram.
1. Are AD and FG in the same plane?
2. Name all the segments parallel to HG .
3. Name all segments skew to AD .
4. Draw CD on the diagram.
5. Mark a point I on the diagram so that AB and AI are opposite rays.
Teacher Solutions:
1.3 Segments, Rays, Parallel Lines and Planes
Part I:
We are going to study figures that are a part of a line.
FIGURE
DEFINITION
Segment
The part of a line consisting of two endpoints
And all points between them.
Give examples, including how to
name the segment
The part of the line consisting of one
Endpoint and all the points of the line on one
side of the endpoint
Give examples, including at least one
ray that goes to the right and one
that goes to the left. Be sure to
show students how to name the rays
Ray
Opposite
Rays
Two collinear rays with the same endpoint.
Note: opposite rays always form a line.
Name the segments
EXAMPLES
Give an appropriate example.
LP , LQ , QP
Name the rays LP or LQ , PL ,
PQ ,
QL or QP
Name a pair of opposite rays PL and PQ
Part II:
Now we will look at the different ways that two lines may or may not intersect.
TYPE OF LINES ARE THEY IN THE DO THEY
EXAMPLE
SAME PLANE?
INTERSECT?
Yes
YES!
Intersecting
Ask
Parallel Lines
Yes
No
Students for
Skew Lines
No
No
Examples.
Skew lines are probably the most difficult to envision. We will make a model to help you see them.
See directions for making model on lesson plan sheet.
EXAMPLE:
Name all segments that intersect DC
ND , GD , HC
Name all segments that are parallel to DC
Name all segments that are skew to DC
AB , GH , JI
JN , JG , IH
Part III:
One last definition.
Parallel Planes are Planes that do not intersect.
Name a plane that is parallel to Plane ABCD
Plane ABCD Plane GHIJ
Name another pair of parallel planes.
Ask students for examples.
Now try answering these questions on your own, using the diagram.
1.
yes
Are AD and FG in the same plane?
2. Name all the segments parallel to HG .
3. Name all segments skew to AD .
DC , EF , AB
EF , HG , BF , GC
4. Draw CD on the diagram.
5. Mark a point I on the diagram so that AB and AI are opposite rays.
and B, to the left of the figure.
I should be collinear with A